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Published November 16, 2023 | Version Published
Journal Article Open

Determination of Rare Earth Element Isotopic Compositions Using Sample-Standard Bracketing and Double-Spike Approaches

Creators

  • 1. ROR icon University of Chicago
  • 2. ROR icon University of Cambridge
  • 3. ROR icon California Institute of Technology
  • 4. ROR icon Boston University

Abstract

Rare earth elements (REEs) have been found to have numerous uses to trace geological and cosmochemical processes through analyses of elemental patterns, radioactive decay, nucleosynthetic anomalies, and cosmogenic effects. Stable isotopic fractionation is one aspect of REE geochemistry that has been seldom studied, with most publications focusing on the development of analytical methodologies for individual REEs, and most applications concerning terrestrial igneous rocks. In this study, we present a method to systematically analyze stable isotopic fractionations of 8 REEs, including Ce, Nd, Sm, Eu, Gd, Dy, Er, and Yb, using sample-standard bracketing (SSB) and double-spike (DS) approaches. All REEs are separated and purified using a fluoropolymer pneumatic liquid chromatography (FPLC) system. We introduce procedures for identifying and correcting some isobaric interferences in double-spike data reduction. Several geostandards, including igneous rocks and sediments, are analyzed using SSB and DS methods. The results indicate that REE isotopic fractionation in igneous processes is limited, except for Eu. Other REEs can still be isotopically fractionated by low-temperature processes and kinetic effects at a high temperature.

Copyright and License

© 2023 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0.

Acknowledgement

We are grateful to C. Liu and two anonymous reviewers for their thorough and constructive reviews, which greatly improved the quality of the manuscript. We appreciate E. Rego for providing the samples from Dales Gorges, Hamersley. This work was supported by NASA grants NNX17AE86G, NNX17AE87G, 80NSSC17K0744, and 80NSSC20K0821 to N.D., NSF grant EAR-2001098 to N.D., DOE grant Tracing the Cycling of Rare Earth Elements to N.D., ERC Advanced Grant, EarthMelt 101020665 to H.M.W., and NERC grant NE/V000411/1 to H.M.W.

Contributions

J.Y.H. and N.D. conceived the study; N.D., F.L.H.T., R.Y., T.J.I., and J.Y.H. developed the FPLC system. J.Y.H. prepared the isotope standard for Eu isotopes, prepared the isotope standards/spikes, and calibrated the spikes for Ce, Nd, Sm, Gd, and Dy isotopes. F.L.H.T. prepared the isotope standards/spikes and calibrated the spikes for Yb isotopes. J.Y.H. did the derivation and modeling, established the measurement protocol, carried out the isotopic analyses, and wrote the manuscript. All authors contributed to data interpretation and writing of the manuscript.

Conflict of Interest

The authors declare no competing financial interest.

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hu-et-al-2023-determination-of-rare-earth-element-isotopic-compositions-using-sample-standard-bracketing-and-double.pdf

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Additional details

Identifiers

ISSN
2472-3452
PMCID
PMC10658628

Related works

Is supplemented by
https://pubs.acs.org/doi/suppl/10.1021/acsearthspacechem.3c00172/suppl_file/sp3c00172_si_001.pdf (URL)

Funding

National Aeronautics and Space Administration
NNX17AE86G
National Aeronautics and Space Administration
NNX17AE87G
National Aeronautics and Space Administration
80NSSC17K0744
National Aeronautics and Space Administration
80NSSC20K0821
National Science Foundation
EAR-2001098
United States Department of Energy
European Research Council
101020665
Natural Environment Research Council
NE/V000411/1

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)